#define _CRT_SECURE_NO_WARNINGS 1

#include<stdio.h>

#include<string.h>

int main() {
    char a;
    int flag = 0;
    while (1) {

        a = getchar();

        if (a == EOF) {
            break;
        }
        if (a == 'b') {
            flag = 1;
        }
        else {
            if (flag == 1) {
                printf("False");
                return 0;
            }
        }
    }
    printf("True");
    return 0;
}